Organo peroxides

ABSTRACT

New methods for the preparation of lactones possessing odoriferous properties and containing 14 to 17 ring carbon atoms in their molecule.

United States Patent Becker Sept. 9, 1975 ORGANO PEROXIDES [51 Int. Cl. C07D 311/94 [75] Inventor: Joseph J. Becker, Geneva, [58] Field of Search 260/3452 Switzerland 73 A F h SA G S l d [56] References Cited ssignee. irmemt. eneva, witzer an UNITED STATES PATENTS 1 Filed= J y 1973 3,528,898 9/1970 Story 260/343 [21] Appl. No.: 377,566 3,546,25] 12/1970 Matsumolto ct a] 260/3452 Related US Application Data Primary Examiner-John M. Ford [62] Division of Ser. No. 41,595, May 28, I970, Attorney, Agent, or Firm-Pennie & Edmonds abandoned.

[57] ABSTRACT [30] Forelgn Apphchon Pnomy Data New methods for the preparation of lactones possess- Muy 29, 1969 Switzerland 8192/69 ing odoriferous properties and containing 14 to 17 May 27, 1970 Switzerland 7865/70 ring carbon atoms in their molecule [52] US. Cl. 260/345.2; 252/522; 260/343;

260/586 M; 204/158 R; 260/3462 R; 260/333; 260/468 K 6 Claims, N0 Drawings ()RGANO IEROXIDES This is a division of application Ser. No. 41.595, filed May 28. 1970. now abandoned.

SUMMARY OF THE INVENTION The invention relates to a new method for the prepa ration of lactones having the formula wherein R" andR" represent hydrogen or one of them a methyl radical and the other hydrogen and u an integer from Zero to 3. and wherein the total of the ring carbon atoms is 14 to 17. and of their unsaturated derivatives of formula DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the invention the method for preparing lactones 111 comprises cleaving by means of the'rmic or radiation energy. or chemical agents a peroxide having the formula 1 wherein R represents hydrogen, a hydrocarbon radical. an acyl group or a group of formula and R representsa group of formula II. provided that when R and R represent a group of formula [1 they are identical. to give a mixture comprising a lactone of formula Ill and the corresponding unsaturated'lactone [Vi or IVii. and either separating the lactone 111 from said mixture or hydrogenating the aforesaid mixture or the unsaturated compound IVi or IVii. separated from said mixture. R. R and n in formula II have the same meanings as in formula III.

The cleavage of peroxide 1 can be carried out by using free radical-initiating techniques, for example. by supplying thermic or radiation energy. or by using reactants which contain unpaired electrons.

The thermal cleavage can be carried out by heating peroxide 1 in the presence or absence of organic solvents at a.temperature comprised between 80 and 150 C. As organic solvents, liquid hydrocarl'ions with the boiling point in the region of 80 C can be comeniently used. Preferably. aromatic hydrocarbons. such as. for example. toluene or xylene. are used. According to a preferred mode of operation a solution of peroxide I in xylene is heated at a temperature comprised between 130 and 150 C. A mixture ofo-. mand p xylcne can also be used.

By thermocleavage peroxide I gives a mixture comprising a lactone having the formula III and the corresponding unsaturated lactone IVi. ii. The ratio of the saturated lactone to its unsaturated derivative varies within wide limits and is dependent on the reaction conditions under which the cleavage of peroxide I is carried out. Forinstance. the influence of the solvent is shown by the fact that when l'l-hydropcroxy-l3- oxabicyclol 10.4.0Ihexadecane is allowedto cleave in solution in m-xylene a mixture consisting of 83.2 '24 of lS-pentadecanolide and 16.8 /1 of l5-pentadec-( l l and l2 )-enolide is obtained. When thesame hydroperoxide is allowed to cleave in solution in p-xylene and o-xylene. respectively. mixtures consisting of 70.8 and (10 of saturated lactone. and:29.2 and 40 .52 of unsaturated lactone are obtained. y

The cleavage of hydroperoxide [can also be promoted photochemically by the action. for example. of ultraviolet light on either the neat hydroperoxide I or a solution of the hydroperoxide I in an organic solvent. As solvents, chlorinated hydrocarbons. such as. for example. chloroform. carbon tetrachloride or trichloroethylene. or ethers, such as dioxan. tetrahydrofuran or monoglyme. can be used.

By photochemical cleavage. as in the case ofthe thermal process. the epoxide I yields a mixture of saturated and unsaturated lactones.

According to another embodiment of the invention. lactones III are obtained by cleaving peroxide I by means of reducing agents.

Suitable reducing agents comprise inorganic ions that can change their valence state by loss of a single elec' tron. for instance, ions of heavy metals, such as iron. cobalt or copper. or reducingagents commonly known to generate nascent hydrogen. for example, metal combinations such as aluminium. manganese. zinc. iron. cadmium. cobalt, nickel. tin or lead and acids. or an alkali metal and an alcohol. eg. sodium or potassium in methanol. ethanol or tert.-butanol. or even an alkali metal sulphite. hydrogen sulphite. thiosulphate. dithionatc or pyrosulphite in the presence of an organic solvent.

It may be assumed that with certain of the cleaving agents mentioned above the cleavage of peroxide 1 follows a mechanism pattern of homolysis wherein the 0-0 bond of the peroxide group cleaves in rder to give the and OR radicals.

The reaction was found to be accelerated in the presbieyclic ethers with hydrogen peroxide in the presence of sulphuric acid at a temperature comprised between about It) and about 25 C. preferably between 12 and [4 C. and allowing the reaction mixture to ence of an alcohol. such as methanol. ethanol. n-propyl W110i 111 thlll P r during 2 -3 minute The alcohol. isopropyl alcohol. n-butyl alcohol. isobutyl al- P 0f f0rim-1111 L Whcfvin h ym l R l'cplccohoL scc,-butyl al oh l cycluhgxy] l h l or mi scnts hydrogen. can be obtained by allowing the bicytures thereof. The temperature at which said reaction V with y t Pemxidc hi the can occur is not critical. It is preferable to operate at Presence ofsulphuric acid at a temperature of about 0 a temperature comprised between about and about C during -3 minut s- 60 C, According to the invention. bicyclic ethers of for- A preferred mode of operation comprises adding. at muld a temperature comprised between 20 and 28 C. to a vigorously stirred aqueous buffer solution of sodium (CHJIU vi sulphite and sodium hydrogen sulphite a solution of 15 i l peroxide l in chloroform and isopropyl alcohol. dccant- 'T' ing the organic phase. extracting the aqueous solution Prepared by m z'ethoxycurhohyl' with chloroform and evaporating the combined organic cyqododcwnonc Compmmd formula extracts to give a mixture comprising laetones Ill and v| Ni. ii. R R

The mixtures of laetones obtained according to the wherein thC symbols R represent hydrogen or one of present invention can be used as such. i.e. without septhem a methyl di l d th other hydrogen. reducaration of their components. as odoriferous substances. ing the resulting di i compound to the corresponddcshcL h i3 Possihlc Sepimhc the Saturated 1g ing carbinol, subjecting the obtained carbinol to saponlaetones fmm its unsaturated dcrivmivc y distilling the T ification and decarboxylation in an alkali solution and obtained mixture by means of a highly effective distillacyclising the resulting kcto alcohol means of an tion column. Furthermore. said mixtures can be hydroacidic agent genated. for instance. by catalytic hydrogenation at According to a preferred mode of opcrmiom the mom temperature in the presence 0f Rhhcy nickel W duction to the earbinol is carried out by means of soalyst. in order to give the saturated lactone as sole dium hOmhydl-idc Product The mixture Ohhhhcd hccmdihg m the hh'ch As acidic cyclising agents mineral or organic acids. tion and their individual components are odorifcrous Such as hydrochlmic acid, phosphoric acid Sulphuric Substances which dcvclop more hr less Characteristic acid. benzenesulfonic acid. p-tolucnesulfonic acid or musk'hkc S trifluoracetic acid. or acidic diatomaceous earths can The starting materials L used in thc l7resent ihvch' be used. Halogens. such as iodine, can also be convetion. can be obtained by treating compounds of fornicmly uscdv muhl The above cyclisation can be carried out by dis- 0 -(H- R solving the product to be cycliscd in the presence ofthe (H910 V 40 acidic agent intoan inert organic solvent such as an aliphatic. a cycloaliphatic. an aromatic. an araliphatic or a chlorinated hydrocarbon. or an ether. such as dioxan. wherein the symbols R and the index n have the same tetrahydrofuran or monoglyme. meaning as indicated for formula ll. with hydrogen per- Acidic diatornaceous earths in hexane are preferred. oxide or; a hydroperoxide having the formula 2-Ethoxycarbonyl-cyclododecanonc. the starting ma- ROOH, wherein R' represents a hydrocarbon raditerial in the above process. can be synthesized from cycal. such as an alkyl. e.g. tert.-butyl. a cycloalkyl. an arclododecanonc. a cheap commercially available prodalkyl or an aryl radical. or an acyl group. eg benzoyl. uct. according to known synthetic methods [c.g. Tetratert.-Butyl-pero.\'ide is preferred. The peroxides of forhcdron 19. I625 i963 mula I wherein R and R are the same and represent Scheme l hcreinbelow illustrates the above described a group having formula II. can be prepared by treating process.

Scheme I C30 ()H H- ((7H, ((."H. .i,.

l (H. ((=O 00( '--('CH..-CHR '--(=o RI ('()O(. ,H,,

NaBH

NaOH i (CH (CH1)...

transl o-hexadec-l l-enolidc.

cisl o-hexadecl 2-enolide, trans-lo-hexadec-lILenoli def cisl 5-methyll b-hexadec-l l-enolidcr transl 5-methyll (w-hexadec-l l-enolide. cis--methyllo-hexadec-l2-enolide. transl 5-methyll o-hexadecl 2-cnolide. cisl o-methyll b-hexadec-l l-enolide. trans-1o-methyl-lo-hexadec-l l-enolide. cisl o-methyll o-hexadecl Z-enolide. transl 6-methyllo-hexadec- 1 Z-enolidc. cis-17-heptadec-l 1 -enolide.

trans l 7-heptadec-l l-enolidc.

cisl 7-heptadecl 2-enolide. trans-17-heptadec-12-enolidc.

eisl o-methyl- 1 7-heptadec-1 l.enolide transl o-methyl- 1 7heptadec-l l-enolide. cisl o-methyl- 1 7-heptadecl 2-enolide. transl o-methyll 7-heptadecl 2-enolide. eisl 7-methyll 7-heptadec-1 l-enolide. transl 7-methyll 7-heptadec-l l-enolide. cis- 1 7-methyll 7-hcptadecl 2-enolide. trans l 7-methyll 7-heptadecl Z-enolide.

The invention will be illustrated in a more detailed manner by the following Examples. in said Examples the temperatures are given in degrees centigrade.

EXAMPLE 1 tilled by means of a Vigreux column and yielded 313' g of a substance containing 89 "/1 of 15- pentadecanolide and 1.1 "/1 of IS-pentadec-(ll and l2l-enolide. lZ-Hydroxy-lS-pentadecanolide (98 g) was obtained as by-product.

The mixture of pentadecanolide and IS-pentadec- (11 and 12)-enolide can be either used directly it stands as perfuming substance or submitted to catalytic hydrogenation in order to obtain complete conversion to pentadecanolidc. ln atypical experimenuthe catalytic hydrogenation is carried out as described hereinbelow. 1

To a solution of 313 g of'a mixture of pentadecanolide and l5-pentadec-( l l and l2)-enolide (obtained according to the procedure described hercabove) in 1.5 litre of methanol. 50 g of a "/r Raney nickel suspension and 5 ml of a 10 "/1 aqueous solution of Na- CO;,

were added and the mixture was shaken in an atmosphere of hydrogen for 3 V; hours. In the above process. 3600 ml of hydrogen were consumed. The reaction mixture was filtered and the clear filtrate evaporated to dryness. The obtained residue was dissolved in 300 ml of ether and 300 ml of toluene and the resulting solution washed with water until neutral, dried over Na SO, and evaporated in vacuo. 31 l g of crude product, con taining ca. 90 "/1 pentadecanolide. were thus obtained.

l2-Hydroperoxy l 3-oxabicyclol 10.4.0 ]hexadecane. used as starting material in the above process. can be obtained as follows:

8 To a solution of l3-oxabicyclol l0.-1.0]hexadecl( l2)-ene (2222 g. 10 Mole) in 10 litres of90 "/1 acetic EXAMPLE 2 A solution of 190 g of di-[l3-oxabicyclo[10.4.0]- hexadecl 2-yl l-pero'xide in 500 ml of xylene was added dropwise to 600 ml of boiling xylene minutes). After cooling, the reaction mixture was evaporated under reduced pressure and the residue distilled to give 139.4 g of a mixture of IS-pentadecanolide and 15- pentadec-( l l and l2)enolide. b.p. l05l07/0.2 Torr.

This mixture was dissolved in 750 ml of methanol and 25 g of a 30 "/1 Raney nickel suspension and 1 ml of a 10 )4 aqueous Na CO solution were added to it. Under the same conditions as those described in Example 1 the mixture was subjected to hydrogenation. One hour was required and 1200 ml of hydrogen were consumed. After the usual treatments lcf. Example 1 139 g of pentadecanolide were obtained.

Di-l l3oxabicyclol 10.4.0 lhexadecl 2-yl l-peroxide. used as starting material in the above process. can be obtained as follows: I

To a solution of l3-oxabicyclol 10.4.0Ihexadecl( l2)-ene (222.2 g. l Mole) in 1 litre of glacial acetic acid at 12, a 52 "/1 solution of hydrogen peroxide (400 g) and 200 g of concentrated sulphuric acid were added (20 minutes). After stirring for 30 additional minutes at 8, the mixture was filtered. The peroxide was obtained as a wet solid product by filtration of the above mixture followed by washing with 450 ml of 50 "/1 acetic acid and water. After drying, 190 g of di-[ 1 3- oxabicyclol 10.4.0 lhexadecl 2-yl l-peroxide having m.p. l346 were obtained.

EXAMPLE 3 36 g of a "/1 solution of tert.-butylhydroperoxide (0.3 Mole were added to a" solution of 13- oxabicyclol l0.4.0]he xadec-l( l2)ene (44.4 g, 0.2 Mole) in 250 ml of acetic acid. To this mixture 15 g of concentrated sulphuric acid and ml of glacial acetic acid were added at such a rate as to maintain the temperature below 14. After having been kept at 10--l2 for 30 additional minutes. the mixture was poured into 1000 ml of ice-cold water and 300 ml of ether and stirred for 10 minutes. The aqueous phase was decanted and extracted with more ether. The combined extracts. after the usual treatments of washing 10 "71 aqueous solution of NaHCO and water) and drying (bl-a 50,). yielded. by evaporation under reduced pressure. 56 g of crude 12-tert.butylperoxy-1 3- oxabicyclol l0.4.0lhexadecane.

A solution of crude hydroperoxide (56 g) in ml of xylene was slowly added under vigorous stirring to 250 ml of boiling xylene (90 minutes). According to the same procedure as that described in Example 1. the

mixture of pentadeeanolide and lipentadce-t l I and 12)-eno1idc was obtained in a 40 yield (relative to l3-oxabicyclol 104.0]hexadec-lt 12 )-cne).

Pure pentadecanolide was obtained by hydrogenating the above mixture according to Example 1.

llUxabicyclol 10.4.0]hexadee-l(12)-ene used for the preparation of the hydroperoxides of Examples 1 -3 and X can be prepared as follows:

A solution of 8 kg of l-br mo-3-chIoropropane in 8 kg of dimethylformamide was added under stirring to a solution of sodium methoxide (2.9 kg, 53.7 Mole) and 2-ethoxyearbonyl-cyclododecanone 12.7 kg, 49.9 Mole) in 55 kg of dimethylformamide. The reaction is exothermic and, by standing 25 minutes, the mixture reached a temperature of 60. 11 was then left at room temperature during one night. The Z-ethoxy-Z-l 3- chloropropyl l-cyclododecanone, obtained in the above process, was not isolated from the reaction mixture but was used as it stood for the next step. After addition of anhydrous sodium acetate (5 kg). the reaction mixture was left under stirring at ll20 during 10 hours, then the dimcthylformamide was evaporated off under reduced pressure. The obtained residue, after dilution with litres of toluene, washing with water and evaporation of the volatile components in vacuo, gave the crude Z-ethoXycarbonyl-Z-l 3-mcthoxycarbonylpropyl |-cyclododecanone.

This product was mixed with 50 litres of water and 27 kg of a 71 aqueous sodium hydroxide solution. The

reaction mixture, after having been kept under stirring at 8590 during 5 hours, was cooled to room temperature and poured into 20 litres of toluene. After separation. the aqueous phase was extracted with more toluene (8 litres) and the combined organic extracts, after the usual treatments of washing and drying, were evaporated under reduced pressure. There were thus obtained 11.3 kg of crude product, which by fractional distillation yielded 9.525 kg of 2-13-hydroxypropyllcyclododecanone, b.p. 138180/0.2 Torr.

A solution of 9.525 kg of 2-1 3-hydroxypropyl]- cyclododecanone and 500 g of 70 benzenesulfonic acid in 30 kg of toluene was heated at reflux for 5 hours under stirring. The water (680 ml) formed during the reaction was directly distilled as soon as it formed. The reaction mixture. after cooling to 20, was washed twice with water and neutralised with 20 litres of a 10 71 aqueous solution of NaHCO The organic phase, after separation and washing with water. was evaporated under reduced pressure to yield 9.370 kg ofcrude product. By fractional distillation, 7.7 kg of 13- oxabicyclol 10.4.0]hexadec-1( 12)-ene. V b.p. 1 l01 14/0.2 Torr, were obtained. The yield. relative to 2ethoxycarbonyl-cyclododecanone, was 69.3 "/1.

EXAMPLE 4 A solution of acrolein 196 g) in 300 ml of methanol was added dropwise at 0-3 to a vigorously stirred solution of 2-ethoxycarbonyl-cyclododecanone (763 g, 3 Mole) and sodium methoxide 15 g) in 2 litres of methanol 1 V: hours). The reaction mixture was then left at 0 during 30 additional minutes. The Z-cthoxycarbonyl- 2-|3oxopropy1]-cyclododecanone, obtained in the above process, was not isolated from the reaction mixture but was used as it stood for the next step.

To the above mixture sodium borohydride (30 g, 0.79 Mole) was added portionwise under stirring at 03, and the solution was kept at this temperature until thin-layer chromatographic analysis (SiO benzeneethyl acetate 9:1) revealed complete disappearance of the starting material.

A 30 71 aqueous solution of sodium hydroxide (330 ml. 3.3 Mole) was added during 20 minutes to the above reaction mixture kept under vigorous stirring. The temperature. which at the beginning of the reaction was at 0, increased up to 20 and it was then brought at 15-70 by means of an external water bath. The mixture was kept at this temperature during 3 hours and the sodium hydrogen carbonate (230 g) which precipitated during the above operation was isolated by filtration. The clear filtrate, after evaporation of the volatile components, gave a residue which, after dilution with 4 litres of water. was extracted with 2 litres of toluene. The organic phase. after the usual treat ments of washing (4 litres of water), neutralisation (200 ml of 25 /1 sulphuric acid) and drying, yielded by evaporation 740 g of crude product. The subsequent fractional distillation of the crude product gave 609 g of 2-1 3-hydroxypropylI-cycltx1odecanone. b.p. 1 15- 160-l65/0.1 Torr. The product thus obtained was used as it stood for the next step. IR: 3420. 1700 cm".

2-13-hydroxypropyll-cyclododecanone (309 g) in 1000 ml of n-hexane was treated with 60 g of acidic diatomaceous earth. The reaction vessel was fitted with a lateral distillation apparatus in order to enable the direct distillation of the water formed during the reaction. 46 ml of water were recovered. After cooling. the suspension was filtered and the solid washed with hexane.

13y evaporation of the volatile components, there was obtained a residue (600 g) which, by fractional distillation, yielded 510 g of 13-oxabicyclol10.4.01hexadec- 1( 12)-ene, b.p. l 16120/0.1 Torr. IR: 1660 cm By replacing in the above process acrolein by methacrolein and by methyl vinyl ketone respectively. 15- mcthyl-l3-oxabicyclo1 10.4.0]hexadec-1( 12)-enc and 14-methyl-13-oxabicyclol 10.4.0 ]hcxadec- 1( 12 )-ene were obtained. The analytical constants of these compounds were as follows: l5-methyl-13- oxabicyclo[ 10.4.0]hexadec-1( 12)-ene: d 0.9623; of" 1.5018.

14-methyl-l3-oxabicyc1ol 104.0]hexadeo l(12)-ene: df" 0.9581; n 1.5037.

EXAMPLE 5 According to the same procedure as that described in Example 1, lZ-hydroperoxy-130xa-14- methylbicyclo[10.3.01-pentadecane (17.3 g) in xylene ml) was decomposed in boiling xylene (100 ml). The residue 18.2 g) obtained by the usual treatment (cf. Example 1 gave by fractional distillation 13.7 g of a mixture of 14-methyl14tetradecanolide and 14-methy1-14-tetradec-( 1 1 and 12)-eno1ide. By hydro genating the above mixture 9 g of pure l4methyl-14- tetradecanolide. b.p. /0.1 Torr, were obtained. This product is a new compound which possesses very interesting odoriferous properties.-

l4-Methy1- 1 Z-hydroperoxy-l 3-oxabicyclo1 10.3 .0 1- pentadecane, used as starting material for the above process was prepared as follows:

To a solution of 14-methy1-13-oxabicyclo{10.3.01- pentadec-l(12)-ene (22.2 g, 0.1 Mole) in 100 m1 of 90 71 acetic acid at 0, at 52 '70 aqueous solution of hydrogen peroxide and 5 g of concentrated sulphuric acid were added under stirring (3 minutes). According to the same procedure as that described in Example 1, 17.3 g of product were obtained. After recrystallisation from ethylacetate the pure l2-hydroperoxy-1 3-oxa- 14- methylbicyclol 10.3.0 Ipentadecane had ni.p. 11 8 120".

14-Mcthy1-l 3-oxabicyclol 10.3.0 lpentadec- 1( 12 )-ene. used as starting material for the preparation of the above peroxide, was obtained as follows: 2- Ethoxycarbonyl-cyclodmlecanone (254.3 g, 1 Mole) in 1000 ml of dimethyl formamide was added to a solution of sodium methoxide (59.4 g, 1.1 Mole) in 801) ml of dimethylformamide. To this mixture allylbromide 132 g, 1.1 Mole) in 200 ml of dimethyll'ormamide was added at 50." under vigorous stirring (2 hours). After standing overnight at 50 under stirring, the mixture was subjected to evaporation under reduced pressure. The residue thus obtained was treated with 750 ml of water and 30 ml of glacial acetic acid and extracted with toluene. By evaporation of the combined organic extracts and fractional distillation of the residue under high vacuum (0.03 Torr), 266.9 g of 2-allyl-2- ethoxycarbonyl-cyclododecanone were obtained, m.p. 5860.

A mixture of 200 g of 2-a1lyl-2-ethoxycarbonyleyclododecanone, 400 ml of ethanol and 300 ml of a 30 7! aqueous sodium hydroxide solution was stirred during 4 hours at reflux temperature. After evaporation of the alcohol at reduced pressure, the mixture was treated with toluene and this solution washed with an aqueous solution of NaCl until neutral. The aqueous phase was extracted with more toluene and the combined organic extracts were evaporated to dryness. The residue thus obtained 136.5 g) gave by fractional distillation l 16.1 g of 2-allyl-cyclododecanone, b.p. 928/0.03 Torr.

63 g. of 2-a1lyl-cyelododecanone were added at 0 over a period of minutes to 600 g of 90 /1 H 80, under vigorous stirring. After 2 additional hours of stirring, the temperature of the reaction mixture was increased to 10, and the mixture was then poured onto water/ice. The extraction with ethyl acetate followed by the usual treatments of washing, drying and evaporation of the combined organic extracts gave a crude product (65 g) which, by fractional distillation. yielded 54 g of 14-methyl-l3-oxabicyclol 10.3.0]penta dec- 1( l2)-ene, b.p. 105/0.l Torr.

EXAMPLE 6 A suspension of 1 Z-hydroperoxyl 3- oxabicyclol 10.4.01-hexadecane (25.6 g) in 500 ml of dioxan in an atmosphere of argon was irradiated during 5 hours by means ofa 125 Watt mercury lamp. During such a process, the reaction vessel was externally cooled in such a way as to keep the temperature of the suspension below There was thus obtained a solution which, after evaporation of the volatile components, gave 28.1 g of a crude material. The subsequent fractional distillation yielded a 1: 1 mixture of 15- pentadecanolide and 15-pentadec-( 1 l and 12)- enolide, b.p. 92/0.1 Torr (18.9 g).

EXAMPLE 7 10 g of di'[ l3-oxabicyclol 10.4.0]hexadec-12-yl peroxyde were irradiated according to the same procedure as that described in Example 6. 1 1 g of crude material yielded by fractional distillation 6 g of a mixture ca. l:l of l5-pentadccanolide and l5-pentadec-(11 and l2)-enolide. b.p. 95--6/0.l0.2 Torr.

EXAMPLE 8 A solution of 665 g of l2-hydroperoxy-13- oxabicyclol10.4.0lhexadecane in 5 litres of chloroform and 1.5 litres of isopropylalcohol was added dropwise (2% hours) to a vigorously stirred neutral aqueous solution (pH ca. 7.0) of sodium sulphite (375 g) and sodium hydrogen sulphite g). The temperature. which at the beginning of the reaction was at 21, increased rapidly to 27-28 and the addition of the peroxide was set at such a rate as to maintain the temperature of the reaction mixture within said range. After subsequent stirring during V2 hour, a thin-layerchromatographic analysis (SiO- benzene/ethyl acetate 9:1 revealed total disappearance of the starting material. The organic phase was decanted and the aqueous solution extracted with 300 ml of chloroform. The

combined extracts were washed twice with 4 litres of a 10 aqueous solution of sodium hydrogen carbonate and water, dried over anhydrous sodium sulphate and evaporated to dryness under reduced pressure.

The residue (860 g) thus obtained yielded 567 g of a mixture consisting of 15-cyclopentadecanolide (ca. 50 "/1), 15-pentadec-(11 and 12)-enolide (ea. 25 "/1), lZ-hydroxy-lS-pentadecanolide (7.6 '71 and 13- oxabicycl0[10.4.0]hexadec-1(12)-ene (17.4 as revealed by vapour phase chromatographic analysis.

The mixture (567 g) obtained in the above process was subjected to hydrogenation according to the same procedure as that described in Example 1. The following quantities were used:

1.5 litres of ethanol g of a 30 /r Raney nickel suspension 30 m1 of a 5 aqueous solution of Na CO 12.5 litres of hydrogen were consumed in a complete hydrogenation period of 17 hours. The residue obtained by evaporation of the volatile components under reduced pressure was diluted with ca. 700 ml of ether and the mixture washed with water until neutral. The organic phase, subjected to the usual treatments of drying and evaporation, gave by distillation 545 g of a mixture, b.p. 155/0.1 Torr, consisting of 15- cyclopentadecanolide (76.2 "/1 12 hydroxy-15- pentadecanolide (8.4 71) and 13-oxabicyclol10.4.0- ]hexadec-l( l2)-ene (15.4

Fractional redistillation of the above mixture gave 380 g of 15-cyclopentadecanolide, b.p. l01105/0.1 Torr.

By replacing in the above process l2-hydroperoxy 13-oxabicyclol l0.4.()]hexadecane by 12-hydroperoxy- 13-oxa-14-methylbicyclol 10.4.0lhexadccane and 12- hydroperoxyl 3-oxal 5-methylbicyclo[ 10.4.0 lhexadecane respectively, mixtures consisting of 15-methy1- l5-pentadecanolide. 15-methyl-15-pentadec-(11 and 12 )-enolide and 12-hydroxy-1 5-methyll 5- pentadecanolide, and 14-methyl-1S-pentadecanolide, 14-methyl-l5pentadec-( l 1 and 12)-enolide and 12- hydroxy- 1 4-methyl-l S-pentadecanolide were obtained with similar yields.

By hydrogenation of said mixtures and subsequent fractional distillation 15-methy1- 1 S-pentadecanolide (d, 0.9399, n,, 1.4700) and 14-methy1-l5- pentadecanolide (d 0.9499. n 1.4728) were obtained.

13 14 IZ-Hydroperoxyl 3-oxal 4-methylhicyclol 10.4.01- hexadecane and IZ-hydroperoxyl 3-oxal 5- KHm u methylhicyclol l0.4.0]-hcxadccanc can he prepared 1 according to the same procedure as that described in Example I for the preparation of l2-hydroperoxy-l3- 5 u oxahicyclol 10.4.0lhexadeeane. They showed the foland represents l of fm'mulll Pwvldcd that l i l i l d m when R' and R" represent a group of formula ll they are l2-hydroperox \'-l B-oxa-l4-methylhicyclol l0.4.0- ident cal. lhexadecane: m.p. l09-l 10. dee. p. ca. l40". 2. The compound l2-hydropcroxy-l3-oxa-l 5-mcth \-'lhic 'clo| l0.4.0 lo lZ-tert-butylperoxy-l3-oxahicyclo 10.4.0] hexalhexadecanc: m.p. l0o-l0l\'. dcc. p. ca. I40. dc an We claim: 3. The compound A l ol the formula di-l l3-oxahicyclo 10.4.0] hexadec-l2-yl] peroxide.

4. The compound l5 IZ-hydroperoxy- 1 3-oxal 4-methylbicyclo l 10.4.0] I hexadecane.

wherein R represents hydrogen. an alkyl. cycloalkyL aralkyl. aryl or acyl radical each containing from l to 7 carbon atoms or a group of formula 

1. A COMPOUND OF THE FORMULA
 2. The compound 12-tert-butylperoxy-13-oxabicyclo (10.4.0) hexadecane.
 3. The compound di-(13-oxabicyclo (10.4.0) hexadec-12-yl) peroxide.
 4. The compound 12-hydroperoxy-13-oxa-14-methylbicyclo (10.4.0) hexadecane.
 5. The compound 12-hydroperoxy-13-oxa-15-methylbicyclo (10.4.0) hexadecane.
 6. The compound 12-hydroperoxy-13-oxabicyclo (10.4.0) hexadecane. 